Clamp operating and locking means



July 15," 1952 Lm I 2,603,323

CLAMP OPERATING AND LOCKING MEANS Filed April 30, 1947 E IN VEN TOR.

1771150771 19. Mvefi HTTORNE).

Patented July 15, 1952 UNITED STATES OFFICE V a V .2,s03,s2s..,f v V CLAMP OPERATING AND'LQ'QKING MEANS;

Anthony A. Muehling, Detroit, Micha A plication April '30, 1947, Serial No; 745,084 4 Claims. (01. 192-8)-,

'This invention relates to operating and locking means for a work piece clamp and has for its vision of an operating and locking means for a work piece clamp'wherein the work is positively held and is not subject to involuntary release by loosening under vibration.

Another obj ect of the invention is the provision of an operating and locking means for a work piece clamp including stationary and rotatable members carrying cam surfaces with which a transversely movable cam member cooperates to provide awedging and locking action with the cam member providing the driving connection between a manual operator and the operating parts of the clamp. V

Other objects and features 01 the invention will be readilyapparent to those skilled in the a'r-t from the specification and appended drawing illustrating certain preferred embodiments in which:-

Figure 1 is a verticalsectional view through the operating and locking means of the present invention, with the clamping elements with which it cooperates diagrammatically shown.

Figure 2 is a horizontal sectional view on the line II'--II of Figure 1,

Figure 3 is a vertical-sectional view on the line IIIIII of Figure 1.

In the drawing there is diagrammatically shown a base I adapted for mounting ina metal working machine, such as a milling machine, shaper, etc., and carrying a work holder 2 in which is disposed a work piece 3 to be clamped in operating position. A clamping arm 4 is rectilinearlymovable in the base I and is operated by a rack Smeshing with-a pinion 6 carried by a shaft I journaled in the base I and keyed to a rotatable hub 8 forming a part of the operating and locking means. 1 i

. Mounted upon the base I is a stationary casing 9 closed by a stationary back plate II through which extends the rotatable hub 8. Interiorly of the casing 9, the hubfi is provided with a' transverse slot I2 in which is disposed a cam member l3 having end portions I4 and I axially ofiset as shown in Figure 1. The slot in hub 8 is closed by end filler piece 16 and top filler piece I1, and between the top filler piece l1 and .the cam member I3 is disposed a spring I8 biasing the cam member l3 transversely.

, end I4 of the cammember will be retracted out of the notch 22 and'will befree to rotate within Within the'casing Qand pinned to the back plate H is a stationary cam plate I9 carrying a short 'steepvcam surface indicated bydottedline T' 2| in Figure 3. The major interior surface'ofthe plate [9 is cylindrical except'for thenotch-at 22 I of which the cam surface 2| forms oneoside It will'be seen, from Figure 1, that the ends IA and I5 of the cam member I3 are offsetsumciently so that the end [4 cooperates onlywith the.

stationary cam plate I9 while the end I5 cooperates with the rotatable cam plate 23. The interior surface of the cam plate 23, as more particularly' shown in Figure 3, is cylindrical in part and includes a camming surface 28 of gradually increasing diameter terminating in a notch 29 of a size to receive the end l5 of the cam member I3. The parts as shown in the drawing are in the locked or clamping position, with the cam member l3 wedging the cam plates I9 and 23 together 7 to prevent retractal rotation of the hub 8, the

wedging being to a degree manually determined by rotation of the handle 25, with the end I5 0:

cammember I3 engagingthe cam surface 28 oi;

plate 23 and the end I4 of cam I3 cam surface 2| of platI9.

To release the clamp, the handle 25 and the hub and cam plate 23 attached thereto are rotated in a counterclockwise direction as-viewed in Figure 3. Thecam member I3 wi1l,'in this engaging the operation, move downwardly asrviewed in Figure 3 under the bias of spring l8 until the end. I5 or the cam member engages'inthe notch 29 in plate 23. Continued jrotationof handler 25 and-plate 23 effects'rotation of thecam.member I3, and,j hence, of the hub 8fin which the cam member is" keyed. This rotates the shaft 'Iandthrough pinion 6, and rack5 elevates the clampingarm 4 to release the workpiece 3; When the end I5 of the cam member I3 is received withinnotch 29, the

the cylindrical portion of the plate] 9;

After the work piece has been removed and another inserted in the work holder 2, it is clamped in position by rotating the handle 25 in a clockwise direction as viewed in Figure 3. In the initial clamping operation, the end [5 of cam member I3 is retainedin the slot 29 so that the rotatable parts move together 'asa unit with the positively rotated cam plate 23-driving the cam member l3 and the hub 8 connected to the cam operated parts. After clamping arm 4 engages the work piece 3 with sufficient force to retract the and I5 of cam member I3 from the notch 29, the hub 8 becomes stationary and the cam plate 23 rotates relative thereto. With a work piece of a thickness within the range for which the lock is designed the end 14 of cam member 13 is now opposite the notch 22 and upon continued rotation of the handle 25 and cam plate 23, thecam member I3 is moved upwardly as viewed in Figure 3 against the bias of spring l8 as the end l5 rides along the cam surface 28 to portions of. decreasing diameter. This transverse rectilinear movement of the cam member l3 continues until the end I4 thereof is tightly wedged against the cam-surface 2| of the notch 22 in the stationary cam plate 19, at which time the clamp is locked by the wedging action of the cam memberl 13 by the engagement of its ends 14 and. with the .camshrfacesZi and..28,. on the stationary androtatable. cam

platesil 9. and 23. In this osition, which isshownl in all of the figures of .the drawing, the work piece issecurely heldin theclampwhich is.pr.evented from retractal movement and fromzinvoluntary releaseby loosening, under vibration. Afterthe working operation the work piece is released in.

the manner originally described.

It will, of course,'be..underst0od thatthe .operating and locking means of this inventionis of the range typeandis designed for-a workpiece of a predetermined range .of. thickness. This range will.be determined by the angular width of the cam surface 2|...andby. the relation between rack Sand pinion 6.

While certain preferred embodiments ofthe invention have been specifically disclosed, it is .un-

derstood that the invention is not limitedthereto, as many variations-will be readily apparent to those skilled in the art-and the-inventionzis to be given its broadest possible interpretationber forreleasably engaging said other end of said driving member [to interconnect said shaft and said rotatable member'to operate the clamp, said shaft becoming stationary as thef'clamp'is engaged whereby saidconnection is'releasedand the driving member 'movedrectilin'early asfit rides along the ,cam surface onsaidjrotatable member to effectlocking of .thelclanipby we'dg ing of the opposi'teendsof the driving member against said stationarycamisurface and the' cam surface on said rotatable member.

2. Operating and locking meansfor. amovable clamp comprising a rotatable shaft 'adapted w operate said clampya driving member-keyed in said shaft for rotation therewith and for moveing member havingcam portions at its opposite ends offset longitudinally of the shaft axis, 'a. stationary cam surface adapted ,to cooperate with one of said cam portions in'the locked posi- '70 ment transversely of the axis thereof, said drivasthe clamp is engaged whereby the driving member thereafter moves rectilinearly only while said other cam portion rides along cam surface on said rotatable member to eifect locking of the clamp by wedging of said cam portions against the stationary and rotatable cam surfaces.

3. Operating and locking means for a movable clamp comprising a rotatable shaft adapted to operate said clamp, a driving member keyed in i said shaft for rotation therewith and for move: ment transversely of the axis thereof, said; driv ing member, having cam portions at its; opposite ends offset longitudinally of the shaft axis, a sta tionary cam plate having an opening receiving said shaft and driving member and provided with a relatively steep cam surface adaptedto be enu :gaged by one of said cam portions in the locked '30 position of the clamp, a rotatable cam platehaving an opening receiving said shaft and; driving member and provided with a cam surface of gradually increasing diameter terminating in a notch receiving the other of said cam portions,

press said other cam portion-against said rotatable cam surface andin said notch, an operating.

handle rigidly connected to said rotatable cam plate, engagement of said other camportion in said notch providing a driving connection for effecting rotation of said shaft by said operating handle to operate the clamp, said shaft becom ing stationary as the clamp is engaged whereby continued movement of the operating handle effects relative movement between said rotatable cam plate and drivingmember to effect rectilinear movement of the driving member. as. said other cam portion rides alon 'the rotatable. cam surface to move said one cam portion intoengagement with the stationary cam surface and effect locking of the clamp ,=b y wedging saidcam portions against said stationary and rotatable cam surfaces.

4. Operating and locking means for a movable clamp comprising a rotatable shaft adapted-to operate said clamp, a driving member keyed in said shaft for rotation therewith andfor movement transversely of the axis thereof, said driving member having cam portions at its opposite ends offset longitudinally of the shaft axis, a

stationary cam plate having an opening therein providing an interior surface receiving said shaft and driving member, the majorportionof said interior surface being cylindrical except ;for a notch thereinat least one side of which is constituted by arelatively steep cam surface, are-- tatablecam plate having an opening thereinproviding an interior. surface receiving said shaft and driving member, the.- interior surface of said rotatable cam plate having an elongated. gradual cam surface terminatingatiits larger diameter in a notch, one of the camportions on said driving member cooperating with the interior surface of.

the stationary cam plate and the stationary cam surface thereon, the other of .said cam portions aeoasas 5 cooperating with the cam surface and notch in said rotatable cam plate, spring means biasing said driving member to press said other of said cam portion against said rotatable cam plate, engagement of said other cam portion and notch providing a driving connection between said rotatable cam plate and shaft for operating the clamp as the cam plate is rotated, said shaft becoming stationary as the clamp is engaged, at which time said one cam portion is disposed opposite the notch in said stationary cam plate, whereby upon continued rotation of the rotatable cam plate the driving member moves rectilinearly as said other cam portion rides along the rotatable cam surface to effect locking of the clamp 15 2,381,480

by wedging of the cam portions against the cam surfaces on the stationary and rotatable cam REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number I Name Date 1,595,499 Birk Aug. 10, 1926 1,900,852 Kuppersmith Mar. 7, 1933 1,946,048 Verderber Feb. 6, 1934 Albrecht et a1 Aug. 7, 1945 

